The present invention relates to an electronically controlled power supply controller for use in an electronic calculator and so on and, more particularly, to a power supply controller useful with a keyboard of the key strobing type.
A prior power supply controller for an electronic calculator is disclosed in U.S. Pat. No. 3,755,806, "CALCULATOR DISPLAY CIRCUIT" patented on Aug. 28, 1973, wherein a display circuit for use in an electronic calculator which includes a computing circuit for receiving and manipulating digital data includes means for automatically turning "off" or "blanking" the display device for the electronic calculator after a predetermined period of time between data entries. The above U.S. Patent discloses a blanking means for automatically extinguishing the display device of said electronic calculator after the lapse of a predetermined period of time.
However, power supply to the computing circuit is not controlled in the above mentioned power supply controller. It is further preferable to control the power supply for the computing circuit because the computing circuit comprising an IC consumes more power than the display device which is made of liquid crystal materials.